“You’re so reliant on that power to make your weekend and your racing much, much easier.

“The first thing you do if you’ve get less power is take downforce off, which means you get more mistakes from the driver’s side – it means there is never a good news story about having less power.

“You’re putting bandaids over bandaids and next minute the bucket of water is on the other side and you’ve got to try to recover that.

“It’s really really tricky to turn up mentally with a big gaping hole in the performance.”

Alonso admitted earlier this week that the Australian Grand Prix, which will get the ball rolling on the new F1 season on Sunday (6am), was likely to be a difficult weekend.

The Spaniard is understood to be committed to the project at McLaren but does have less than a year left on his deal and Webber thinks he could very easily pull the plug.

“Fernando is capable of anything,” added Webber, who will act as a commentator for Channel 4 this year.

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Mark Webber believes the slow car will force Fernando Alonso out of McLaren

“He’s been round the block and it’s highly frustrating for all of us to see a guy of his level – and Stoffel Vandoorne – in these struggles.

“I’d love to see both of them up there.

“That McLaren would be just mint nestled in those first three rows and juking it out every weekend with Red Bull, Ferrari and Mercedes.

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Fernando Alonso will find out just how competitive his McLaren is or is not this weekend

“Both drivers are capable as are the McLaren team.

“Could Fernando walk away? He is his own man and he could wake up one day and make a rash decision.

“It’s really testing him mentally at the moment.”

***Channel 4 is the home of free-to-air Formula 1 in the UK with live coverage of 10 Grand Prix this season and comprehensive highlights of every race weekend. You can watch the highlights of the Australian Grand Prix on Channel 4 from 2pm on 26th March. For more information visit here***